/*  mbed Microcontroller Library
    Copyright (c) 2006-2013 ARM Limited

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
#ifndef MBED_BUSOUT_H
#define MBED_BUSOUT_H

#include "DigitalOut.h"

namespace mbed {

    /** A digital output bus, used for setting the state of a collection of pins
    */
    class BusOut {

      public:

        /** Create an BusOut, connected to the specified pins

            @param p<n> DigitalOut pin to connect to bus bit <n> (p5-p30, NC)

            @note
            It is only required to specify as many pin variables as is required
            for the bus; the rest will default to NC (not connected)
        */
        BusOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
               PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
               PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
               PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);

        BusOut(PinName pins[16]);

        virtual ~BusOut();

        /** Write the value to the output bus

            @param value An integer specifying a bit to write for every corresponding DigitalOut pin
        */
        void write(int value);

        /** Read the value currently output on the bus

            @returns
              An integer with each bit corresponding to associated DigitalOut pin setting
        */
        int read();

        /** Binary mask of bus pins connected to actual pins (not NC pins)
            If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1

            @returns
              Binary mask of connected pins
        */
        int mask() {
            return _nc_mask;
        }

        #ifdef MBED_OPERATORS
        /** A shorthand for write()
        */
        BusOut& operator= (int v);
        BusOut& operator= (BusOut& rhs);

        /** Access to particular bit in random-iterator fashion
        */
        DigitalOut& operator[](int index);

        /** A shorthand for read()
        */
        operator int();
        #endif

      protected:
        DigitalOut* _pin[16];

        /** Mask of bus's NC pins
            If bit[n] is set to 1 - pin is connected
            if bit[n] is cleared - pin is not connected (NC)
        */
        int _nc_mask;

        /* disallow copy constructor and assignment operators */
      private:
        BusOut(const BusOut&);
        BusOut& operator = (const BusOut&);
    };

} // namespace mbed

#endif
